FUNCTION: [Summary is not available for the mouse gene. This summary is for the human ortholog.] The protein encoded by this gene is a ryanodine receptor, which functions to release calcium from intracellular storage for use in many cellular processes. For example, the encoded protein is involved in skeletal muscle contraction by releasing calcium from the sarcoplasmic reticulum followed by depolarization of T-tubules. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Sep 2011] PHENOTYPE: Homozygotes for targeted null mutations exhibit impaired muscle contraction at an early age, changes in hippocampal synaptic plasticity, increased locomotor activity with a tendency to circle, and impaired relearning of a spatial task. [provided by MGI curators]